StaticFiles support for directories other than "statics"

Checklist

• [/] There are no similar issues or pull requests for this yet.
• [X - tried to get feedback but no replies] I discussed this idea on the community chat and feedback is positive.

Is your feature related to a problem? Please describe.

I want to be able to serve static files from arbitrary locations within a python package but I can’t because currently it looks in a statics folder which is hardcoded.

Describe the solution you would like.

I’d like to be able to pass as a parameter the path within the python package to look in for the static files.

Describe alternatives you considered

I’ve considered changing the location of my packaged files to statics but this will have knock on effects across other systems, and statics itself is non-standard as far as I can tell.

Additional context

[florimondmanca]

Hi folks, we’re considering #1350 and the following API to address this use case…

routes=[
    ...
    Mount('/static', app=StaticFiles(packages=['bootstrap4', ('mypackage', 'dist')]), name="static"),
]

That is, we’ll be able to specify a root directory to look into as a 2-tuple (<package_name>, <dir>) form, where the single string "<package_name>" uses the current default, "statics".

Any thoughts or comments welcome on the PR before we move on and merge. 😃

[paulmsmith]

I found that by simply creating an empty directory called statics inside the dependancy this then worked and seemed to allow me to reference things in static within the dependancy. This feels like bug to me and as @bram2000 said, would be helpful if you could pass a parameter specifying the directory within a dependancy you need to include things from.